Saturn’s moon Titan has lakes on its surface and a thick atmosphere, but there’s one more way this cold, distant world is like the Earth: It appears to have volcanoes—though they’re a little chillier than Eyjafjallajökull.

“We finally have some proof that Titan is an active world,” said geophysicist Randolph Kirk of the U.S. Geological Survey, who presented the findings. [NPR]

The place is called Sotra. It may have the look of an Earth volcano—a 3,000-foot-tall mountain with a crater in the middle—but this mountain isn’t erupting with liquid hot magma. The surface of Titan is nearly -300 degrees F, and the cryovolcano could be erupting water ice and ammonia.

Earth’s interior is divided into distinct layers of rock and liquid magma. When this molten rock erupts through the planet’s crust, it’s known as volcanism. Titan’s volcanism is more complicated because beneath the moon’s surface lies a layer of ice. Even a small amount of internal heat could create molten ices. Because the liquid would be less dense, it would force its way to the surface. The result would be a massive eruption of slushy liquid and gases similar to what scientists have seen on other icy moons. [New Scientist]

But there’s a lot astronomers still don’t know about these formations, according to planetary scientist Jeffrey Kargel: whether the eruptions are slow and gentle or quick and violent, whether Titan’s volcanism is still going or has died out, or what the texture of the flows is really like.

He said that if the lavas were rich in hydrocarbons, they could have the look of softened asphalt, candle wax or even polyethylene. “There are many unanswered questions and intriguing possibilities,” he told reporters. [BBC News]

Even a small amount of internal heat could create molten ices. Because the liquid would be less dense, it would force its way to the surface.
Isn’t water denser that the ice, ice floats. Maybe mixed with ammonia and other things, the density change gets flipped.

Darius2025

@ Chris: Only if the ice is water-ice, which seems to be special for some reason we can’t yet fathom.

quarksparrow

@Darius2025: The reasons why ice is less dense than water are pretty well understood. Not sure why you’d say that.

Katharine

Nitpick: The mantle is actually kinda solid. Magma develops within the mantle or crust when temperature-pressure conditions favor the molten state.

starwindwalker

Ammonia keeps the freezing temperature of water down to make it “molten”. Thermal processes are likely involved as well, and definitely responsible for eruptions; to what extent is what will be most interesting. All the ingredients are present for amino acids to form; methane, hydrogen, nitrogen & water; yet the rock-hard, ice surface is too frigid. Perhaps vast sub-surface, slush lakes or “oceans” exist beneath the ice, at temperatures friendly to the formation of organic compounds.